Router-ASUS-RT-N66U

From AAISP Support Site

IPv6

The RT-N66U does pretty much "just work" with IPv6. Running the TomatoUSB firmware it was just a case of enabling "Native IPv6" in the IPv6 options and giving the router's LAN interface an address from the allocated /64. The router appears to have enabled RA by default, so everything on the LAN side "just works"